Flat bottom bag with handle

ABSTRACT

A tubular sleeve is shaped with a pair of opposing faces, a pair of opposing side walls, and a lowermost terminal edge. Double gussets are simultaneously formed on each opposing side walls of the shaped sleeve inward between the pair of opposing faces of the shaped sleeve and defining substantially square corners at intersection of the longitudinal ribs of the shaped sleeve and the lowermost terminal edge of the shaped sleeve. The square corners of the shaped sleeve are relieved and removed to form a flat bottom. A pair of handles are unitarily formed and integral with the frontal faces extending over the open top.

RELATED APPLICATION

[0001] The present application is a division of my originally filed application Ser. No. 09/307,990, filed May 10, 1999, entitled PLASTIC SHOPPING BAG. Ser. No. 09/307,990 is still pending.

BACKGROUND OF THE INVENTION

[0002] The present invention relates to the construction of a flat bottom plastic shopping bag constructed unitarily with a handle and to the method for making the bag.

[0003] Plastic shopping bags have supplanted paper bags for use in supermarkets, and most retail establishments, because of their versatility, decorativeness and cheapness. Generally, such bags, have a disadvantage in that they are formed with hanging triangularly shaped bottoms and are thus difficult to fill. It has been attempted to provide plastic bags having flat bottoms, for more conveniently receiving grocery items, boxes and the like. Such bags, however, cannot be made inexpensively. Another problem with conventional plastic bag lies in the fact that they are not self supporting and therefor their opening or mouth is neither wide or distensible enough to make loading or filling of the bag easy.

[0004] In my prior patents, U.S. Pat. Nos. 3,988,970, 3,916,770 and 4,230,030, I have disclosed plastic bags and their manufacture in which flat bottoms have been formed. These serve to allow the bag to be neatly folded for stacking and shipping and also to effective an advantage in filling the bag. The bags shown in these patents also have side gussets similarly designed to allow folding and stacking for shipping. The bags known from these patents, however, do not provide reinforced strong integrally and unitarily formed handles, by which the filled ba can be easily carried.

[0005] It is the object of the present invention to provide a plastic bag overcoming the disadvantages of the prior art bags.

[0006] It is a further object to provide a plastic shopping bag having an integrally formed handle allowing the user to carry a full bag with ease and comfort.

[0007] The foregoing objects together with other objects and advantages will be apparent from the following disclosure of the invention.

SUMMARY OF THE INVENTION

[0008] According to the present invention, the foregoing objects and advantages are obtained by forming a plastic bag with a generally rectangular cross section having multiple gusseted side walls and a flat bottom.

[0009] The plastic bag comprises a tubular sleeve shaped to be rectangular in transverse cross section and having a pair of opposing faces and a pair of end walls. Each end wall is formed with at least a pair of longitudinal gussets. The gussets are folded inwardly and the tubular sleeve flattened by pressing the opposing faces together. In this condition the corners formed by the intersection of the lower edge and the side walls are removed, and the side walls and the bottom are further sealed and shaped to form the closed flat bottom.

[0010] The bag is finished by providing it with a unitary integral handle by cutting or scoring the bag along a line from the side walls toward but spaced from the central longitudinal axis and spaced below the topmost edge of the plastic. In use the plastic sheet is separated along the score or cut lines freeing the material in the space above the score or cut lines, thus forming a handle. Reinforcement ribs or seal members and the like can be provided to strengthen the material particularly at the juncture of the handle, score lines, etc.

[0011] Full details of the present invention are set forth in the following description and shown in the accompanying drawing.

BRIEF DESCRIPTION OF THE DRAWING

[0012] In the Drawings

[0013]FIG. 1 is a perspective view of a plastic sheet rolled into a cylindrical tube;

[0014]FIG. 2 is a similar view showing the cylindrical tube formed into a rectangular tubular sleeve having frontal faces, end walls and double gussets;

[0015]FIG. 3 is a planar view of the tubular sleeve, illustrated in FIG. 3 showing the sleeve in flattened form and the bottom corners removed;

[0016]FIG. 4 is a perspective view particularly cross sectioned showing the lower portion of the bag with its relieved lower corners being folded over the flat bottom in forming the bottom wall;

[0017]FIG. 5 is a perspective view looking at the bottom wall with the relieved corners seated together forming the flat bottom;

[0018]FIG. 6 is an isometric view partially broken away to show its interior and illustrating the distention and ballooning of the gussets;

[0019]FIG. 7 is a view similar to that of FIG. 3 showing the formation of the handle for the bag; and

[0020]FIG. 8 is a view similar to FIG. 6 showing the bag with handle open.

DESCRIPTION OF THE INVENTION

[0021] The resultant bag of the present invention will be most easily understood by first detailing the several steps depicted in FIGS. 1-6 by which the bag is made.

[0022] In accordance with the present invention, a cylinder 10 is formed of an endless sheet of plastic film, suitable for use as a commercial shopping bag. The sheet 10 was initially laid flat and cut to the desired longitudinal size, and this flat condition, the bottom edge 12 is passed through a heating or shaping unit where several ribs and/or seal blocks 14 are formed in a uniform spaced arrangement in a relatively wide band 16 adjacent the edge 12. The ribs and seal blocks 14 strengthen the film and serve to form a reinforced bottom, as will be described.

[0023] The sheet 10, rolled into a cylinder, is then sealed along the longitudinal adjoining edge 18 to provide a unitary cylindrical body, open at both ends. The cylindrical body is thereafter placed into a forming or creasing machine in which a plurality of longitudinal edges 20 are formed “squaring” the cylindrical body into a tubular sleeve 22 having a rectangular cross-sectional configuration with opposed frontal faces 24 and opposed narrower end walls 26. At the same time that the edges 20 are formed and the body squared, the end walls 26 are each folded along longitudinal gusset rib 28 to form with the longitudinal edges 20, a pair of gussets 30 having alternating longitudinal ribs and folds. Preferably, the ribs 20 are reinforced by heat to form a somewhat rigid longitudinal back, which allows the sleeve to stand when opened.

[0024] The bag is once again laid generally flat (FIG. 3) with the bottom edge 12 open and the gussets 30 running completely along the length of the bag. At this stage, with the closed gussets 30 in place, the bag is sealed at its bottom edge 12 thereby closing the tubular sleeve 22. (See FIG. 5). Simultaneously, angular inwardly directed cuts 32 are made, severing the corners 34 of the bag at the intersection of the bottom 12 and longitudinal edges 20. The severed corners 34 are removed and the adjacent tapered gusset folds 28 and the end ribs 20 are heat sealed to each other and to the bottom edge 12 insuring that the bag's integrity is reestablished (See FIG. 5).

[0025] Lastly a folder or mandrel is employed to form and flatten the bottom wall, about a horizontal line 40 approximately at the point 42 where the upper edge of the cut 32 intersects the gusset ribs. Because the angular cut edge of the gusset ribs and folds are sealed, the side walls 26 are pulled downwardly into the plane of the bottom the sections 42 and 44 provide triangular sections defining laterally extending wing portions 44 at the bottom wall, as seen in FIGS. 5 and 6. Consequently, once the bag is opened the “foot” F of the flat bottom of the bag (FIG. 6) is larger than the rectangular cross-sectional configuration of the tubular sleeve itself, resulting in a large volume bag without substantial increase in the sleeve diameter. It will also be seen that the ribs and block seals 14 formed in the bottom edge of the tubular sleeve (FIG. 2) now create a strong reinforcement for the bottom wall and extensions creating a firm, well defined rectangular foot. The seals along cuts 32, like form reinforcing ribs strengthening the triangular extension wing portion 44.

[0026] Similarly as seen from FIG. 6, the mouth 48 or top edge of the bag is widened considerably once the bag is opened so as to allow more ready access into the bag itself. This is accomplished by the fact that when the bag is opened and the bottom wall flattened, the gusseted end walls 30 balloon outwardly and distended both transversely and laterally. Thus compared to a single gusseted bag, the present bag provides a substantially greater volume within the bag without increasing the tubular diameter or the flat dimensions of the bag. By reinforcing the longitudinal corners 28 with a heat formed bead or seal, added provide vertical strength in provided allowing the bag to remain open without difficultly.

[0027] By forming the bag with double gussets, a wide mouth and wide body bag is formed easily and inexpensively. While two gussets are illustrated at each end it will be apparent, that more than two can be formed with little difficultly or modification. The gussets are actually smaller than would be expected and fold only a short distance inward between the frontal walls. When the bag is opened, the gussets however allow the bag to open squarely, i.e., the frontal walls and the side walls stand perpendicularly to the horizontal, even larger than the initial cross-section.

[0028] Although, multi-gussets are formed providing at least six layers of film, when laid flat, the bottom wall is not encumbered with material. This is so because the corners are cut on the bias and excess material removed. This has an added advantage, as well, when the bag is opened, the angular walls of the bottom can open wide forming in effect a part of the bag bottom; increasing the wide and flat bottom perfectly.

[0029] The present bag is provided with self or integral handles 50 as seen in FIGS. 6 and 7. In the flat condition, the gusseted tubular sleeve 22 or the finished bag is scored or cut along transverse lines 52 from each end wall inwardly toward each other, for a selected distance terminating, spaced from the central longitudinal axis of the frontal faces. This produces a pair of spaced handles 50 integrally and unitarily formed at 54 with the frontal faces 24 of the bag. To insure that the handles 52 do not tear away from the frontal faces reinforcing ribs 56, reinforced edges or the like may be made at the corners 58 or along the longitudinal junction 54 of the handle and the bag, by heat sealing the edges adding additional material or other conventional means. The scoring or cutting as well as the reinforcement of the handles can be effected simultaneously with the formation of the flat bottom bag.

[0030] While the invention has been illustrated and described as embodied in a method of making a bag having a flat bottom and double or more side gussets, however, it is not limited to the details shown, since it will be understood that various omissions, modifications, substitutions and changes in the forms and details of the device illustrated and its operation can be made by those skilled in the art without departing in any way from the spirit of the claims attached. 

What is claimed is:
 1. A plastic shopping bag comprising a tubular sleeve having an open top, a closed bottom, a pair of opposing frontal faces and a pair of opposing side walls connecting said frontal faces, each of said side walls being provided with at least one pair of gussets formed of alternating longitudinal ribs and folds allowing the sleeve to be compactly folded for storage and when in use opened and distended to provide a wide mouth, and a flat bottom, said bag being unitarily formed with at least two handles joined to the frontal faces and extend across the open top between the frontal faces.
 2. The bag according to claim 1 , wherein said handle is formed integratedly and unitarily with said bag.
 3. The bag according to claim 1 wherein said bottom is reinforced with transversely directed ribs and sealing blocks, and provided with angular cuts adjacent to the intersection of the bottom and the side walls, relieving the corners of said bag, said corners being removed and the adjacent edges sealed together forming the flat bottom.
 4. The bag according to claim 3 wherein the corners of said bag and the terminal end of the side walls form a laterally extending portion from the bottom wall when said bag is opened.
 5. The bag according to claim 4 wherein said end walls balloon outwardly when said bag is cross-sectional area.
 6. A method of making a flat bottom plastic shopping bag having handles comprising the steps of: (a) providing a unitary tubular sleeve; (b) shaping said unitary tubular sleeve with a pair of opposing faces, a pair of opposing side walls, and a lowermost terminal edge; (c) simultaneously forming i. double gussets on each opposing side wall inwardly between said pair of opposing faces so as to form alternating longitudinal ribs and longitudinal folds; ii. at least two handles joined to the opposing frontal faces and extending over the open top; (d) removing the triangular flaps forming the corner of the lowermost terminal edge and sealing said terminal edges so as to define a flat closed bottom.
 7. The method as defined in claim 6 wherein said handles are formed by cutting the tubular sleeve spaced from the open inwardly from said side walls to a point spaced from the center of said frontal faces.
 8. The method as defined in claim 6 wherein said tubular sleeve is formed from a flat plastic sheet by joining the edges of said plastic sheet along a longitudinal line. 